It is known to utilize ultraviolet (“UV”) light to sterilize needles, catheters and other medical devices, to thereby reduce the risk of infection to patients. Such practice has also been applied to food, air, water, and other items, although in these other instances the effect is usually to disinfect rather than to sterilize. UV emitters can be stationary or portable, and can range in size from very large devices through which entire pallets of material can be processed, to small hand-held wands for home use.
Surprisingly, existing UV emitter stations are impractical to disinfect publicly used equipment, despite the number of microorganisms that has been found to exist on surfaces including enteroccocus faecalis, escherichia coli, legionella pneumophila, legionella bozemanii, salmonella enteritidis, salmonela paratyphi (enteric fever), salmonella typhosa (typhoid fever), salmonella typhimurium, staphylococcus aerius, e. coli, and rotavirus. For example, known handheld UV emitters have insufficient power to conveniently disinfect a shopping cart, let alone dozens of carts. As a result, the present efforts at grocery stores, amusement parks and so forth are directed to annual or semi-annual spray washing, which may or may not include application of antiseptic chemicals. This is problematic as such dirty equipment exposes the public to harmful bacteria and other microorganisms.
In an attempt to reduce the public's exposure, stores and other locations provide sanitary wipes that can be used by individual customers to disinfect publicly-used equipment. However, each wipe is only minimally effective, and wipes are impractical for cleaning more than a small portion of a piece of equipment.
U.S. Patent Appl. No. 2007/0012340 to Jones discusses a system for cleaning shopping carts and other reusable items that includes a plurality of steps, such as rinsing and drying the carts, and then subjecting the carts to pulses of UV light. Although the Jones system could be useful in cleaning dirty carts, the system is disadvantageous for simply disinfecting carts because the many components have large energy requirements, and the overly complex system will likely lead to higher maintenance costs. Jones and all other extrinsic materials discussed herein are incorporated by reference in their entirety. Where a definition or use of a term in an incorporated reference is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply.
U.S. Patent Appl. No. 2006/0186358 to Couvillion discusses a disinfecting system that uses a single UV light source to disinfect shopping carts. Although the Couvillion system reduces energy costs compared with the Jones system by using only a UV light source, the Couvillion device fails to sufficiently disinfect an entire cart due to the minimal UV light source mounted along the ceiling.
It is known to use a plurality of UV lights to decontaminate objects. For example, U.S. Pat. No. 5,958,336 to Duarte and European Patent No. 0755271 to Shodeen discuss surface sterilization devices that can utilize UV light to decontaminate items as they are conveyed from a contaminated area to a clean area. Although the devices apparently suffice in decontaminating the objects, the high number of UV lamps used will increase usage and maintenance costs of the device, and the V-shape configuration of the reflectors would likely be insufficient to disinfect a non-moving object.
U.S. Pat. No. 6,649,921 to Cekic et al. discusses positioning a UV light within a reflective trough that has reflective sections disposed about the trough in order to provide substantially two-dimensional uniform radiation of a planar surface. However, the Cekic apparatus is configured to direct UV radiation to a planar surface at a set distance, and would likely be insufficient to irradiate non-planar surfaces at varying distances from the UV light source.
Thus, there is still a need for improved disinfection methods and apparatus for use on publicly-used equipment.